This invention generally relates to probabilistic models for calculating wire density in different areas of a datapath or hardmac, and more specifically relates to a probabilistic model which differentiates between horizontal and vertical segments.
FIG. 1 shows a general datapath structure. As shown, datapath cells are located in blocks (clusters) and control cells may be located in columns along left and right sides of the datapath and in blocks as well. Current datapaths are typically very large and complex, and require design datapath macros with complex hierarchical structures that have a high design quality. Additionally, complex constraints on the placement of cells, pins and nets, as well as the size of gaps between cells, blocks, etc. must be respected, and there must be guaranteed 100% detail routing.
One prior art approach for calculating wire density in different areas of a datapath is based on a simplified density model and is used for placement quality estimation only. The approach is not accurate, does not differentiate between vertical and horizontal segments of connections, does not take into account all possible shortest length configurations of connections, and is unacceptable for calculating a congestion map.